Wall corner forming tool



Nov. 4, 1952 s. T. sHlELDs WALL CORNER FORMING TOOL 2 SHEETS- SHEET l Filed Aug. 18, 1949 IN V EN TOR.

NOV. 4, 1952 s T, sHlELDS 2,616,285

A WALL CORNER FORMING TOOL Filed Aug. 18, 1949 2 SHEETS--SHEET 2 Patented Nov. 4, 1952 UNITED STATES PATENT 2,616,285

WALL CORNER FORMING rroo-L samuel T.- siiieids, Cleveland; ohio App'nca-tion Augustis, 1949, seriane.. 1i,921.

8 Claims.

The general object of the present invention is the provision of a plaster or cement trimming tool which will form the inner and outer plaster, tape or cement trimmed corners of dry constructed building wallsA formed of wall board with a minimum of labor.

More specifically my invention. is concerned with. the provision of a tool for the purposes stated. and which is adapted to utilize the hard, adjacent surfaces of abutting p-anelsin the corner structures as bea-ringand gaugingsurfaces, and'against which associated blade portions ofthe tool are manually flexed to bring the corner forming edges. oi the tool into an apex forming relationship and which will bel substantially coincident with the line of intersectionL of the adjacent, or abutting corner panels.v e

A further objectv is the provision of a. manually flexible multi-blade. tool for the purposes stated and which will form substantially accurate cement, tape or plastercornerswhile eifecting a feather edged joint between the plastic man terial and the hard panel surfaces, thus eliminating the major part of the time heretofore consumed by the building,mechanic. in sanding down the cemented. or. plastered joint.`

A still further' object of my invention is` the provision of a light-Weight manual tool-which` will be balanced in use while being sufficiently flexible to be sensitive to ready manipulation by the building mechanic without resulting fatigue.`

Other objects and advantages of the invention will be apparent from the following, detailed description of preferred forms of embodiment of the invention, reference being made tothe accompanyingA drawings wherein- Fig. 1 shows a face or front elevation ofA my in'- vention as embodied in a tool for the formation of outside corner joints;

Fig. 2 is a front end View of the tool.

Fig. 3 is an elevational illustration of the position of the tool when flexed to form an outsidev corner joint;

Fig. 4 is a perspective View and shows an embodiment of the invention as applied to a tool` for the formation of inside. corner joints;

Fig. 5 is a forward or end View of the tool.

shown in Fig. 4;

Fig. 6 is a front elevation of the tool shown light-weight tool for building mechanics which is so simple in function and operation as to not (C1. 'ia-:isti

require any extensiveskill in its use. The praetice in finishing.. up or foiinin the joints between the abutting. edges' ofv dry wall and ceiling structures heretofore h as involved. so much manualA labor as to detractl from the known advantages in the use of wall board as compared to the lathing and plasteringl of Wet wall structures'. Therifiechan-ie,T if he be a plasterenewill' use the well' known trowelig nr'lethd'sA in filling" in the joints between they abutting edges of the paneliA and. all of has tb sanded down after they plaster hasd-ried. Shoiild the mechanic be a painter he Willuse a4 spatula or broadv tool for' filling and smoothing and evntiiallsandme outside corners.

i I. provide an inexpensive tool" which will wipe the plastic joint material downto a feather edge relative to the surfaces of the :abutting: panels While simultaneously' forming a finishedinsid'or' Outside Cornel. This is effected using, SWO t'rowlng blades of fl'ei'bl nialielal.A the Suf-faces of which arerelatively disposed at anangle which. is non-coincident with the. corner wall angle to be finished. While the. principle of operation is the same for formingboth inside and outside corners, provideseparatetools: for forming the respective corners. Thus in- Fi'gs.. 1,;y 2 and 3` of the drawings Iv` have shown an` embodiment of the invention which visA adapted to the for-mation ofoutside. corner joints, whileA in Figs. 4 tol in# c1usiVe, IvI show anembodimen-t .adapted to the'I formation of inside cornerv joints. It is to be:y

understoodthat while I hereinafterlwill kdescribe thet tools as comprising. primarily flexible metal-v` blades,l other flexiblel materialsffmay befound` satisfactory. A

Referring specically to the tool-` for forming. outside corner joints andasshownin Figsll to-3 inclusive,` I construct the troweling part of-.thef

tool of a sheet of springY metal.l of about .'015- toA .Q25 of anvinch thickness. thetoughshape. shown whereby a flexible left' blade Nanda Hein? ble right blade are disposed to have an included dihedral angle I, which is less than and accordingly non-coincident with the included angle between the surfaces of the two abutting wall panels which comprise the outside corner structure W to be finished. These blades and may comprise a single sheet of material bent into the trough shape shown or may comprise two separate blade pieces secured to any suitable fastening means. I prefer, however, that separate angle abutting blades be used whereby the tool will be more suitable for plastered edges and for tape reinforced edges which may be plaster pointed or trimmed.

In the structure shown these blades l0 and are secured to a bracket formation I4 comprising part of handle structure l5, the blades being secured thereto in any suitable manner, such as riveting, spot welding, or by other means. When the blades are separate the tool can be made more sensitive.

'Ihe forward corner forming end edges of the blade members I0 and are tapered to the extent of about to converge at an apex or point A, and in this instance of use the blade edges slope from the side margin thereof inwardly and downwardly to the apex A, the resulting angl-ev between the corner-forming or trimming edges being less than the plane angle of the dihedral angle formed by the blades. The shape is such that two forwardly extending flexible lips or parts Il)a and ||a are thus provided which comprise twoilexible wall bearing portions which bear against the surfaces of the abutting corner panels between which the joint is being formed or shaped at the apex A of the tool. The disposition or angle of the entire tool relative to the perpendicular wall surfaces when in use is shown in Fig. 3. The blades along their abutting edges will be flexed apart only a slight amount when substantial pressure is exerted by the user and a slight amount of plaster may escape therebetween. A second stroke of the tool with less applied pressure will eliminate any slight corner ridge which may result. If a reinforcing tape is used the tape will be corner formed and practically no plaster passes the slightly spread-apart blades.

The tool is applied to the corner wall panels after plaster or cement with some surplus has been applied to the corner or joint void to be fllled and the mechanic presses upon the tool with Vsuiicient manual effort to cause the end portions ||la and ||a to be ilxed to a sufficient extent to 'bring the apex point A substantially coincident with a vertical intersecting line of the two planes of the wall panels forming the end corner structure of the wall.

By having `the forward or operating edges of the tool shaped or tapered in the manner disclosed in thel drawings two functions are obtained. The' edges and adjacent portions serve to define or form the corner joint of plaster. Since the outer reaches of the portions ||la and Ila contact the wall surfaces first, greater pressure is exerted at the outside, gradually decreasing to the apex point A, thus causing the plaster` corner joint to be formed as the tool is drawn downwardly. while also forming a feather edge plaster formation relative to the surfaces of the corner wall panels. I

It is to be understood that while I have shown the tool in Fig. 1 as being designed to form substantially right-angle corner joints, the included angle can varyshould it be ldesired to form outside corners which are not right-angle wall corners. Wall specifications would determine the number of tools which should be provided for a given job.

The inside corner joint former shown in Fig. 4, insofar as angular disposition of the troweling blades is concerned, is about the reverse of the tool shown in Fig. 1. Thus, the blades 20, 2| are secured to the bracket formation 22 formed on the handle 23 and the included dihedral angle in the trough of the blades is greater than 90. A tapered space indicated by the numeral 25 is provided between the inner adjacent edges of the two blade members. In this form of the tool the forward flexible ends 20a and 2 |a of the blades 20, 2|, respectively, slope away from the trough center of the tool. When the tool is pressed into a right-angled corner the blade ends 20* and 2|*EL are flexed by manual effort, thus forcing the blades together to close the tapered space 25. The manual eort of thus deilecting the blades to bring their corner forming apex ends together thus causes the forward tapered edges of the flexible blades to trowel the plaster of the joint down to a feather edge relation to the surfaces of the corner panels of the wall structure.

As shown in Fig. 4 I provide a back-up or stop 26 which may be integrally formed on the handle structure 22--23, with the end 2lia thereof spaced relative to the back faces of the flexible blades 20, 2| the right amount to support the flexible j blades at the apex point where they have been flexed together. The manner of using the tool shown in Fig. 4 is substantially the same as that illustrated in Fig. 3. Any suitable grip means, such as a grip member 30, may be applied to the handles I5 and 23.

I have found that tools such as I have herein disclosed can be constructed of sufficiently light weight to afford convenient deilecting and stroking manipulation thereof by a mechanic without fatigue. The tool may be of balanced design by having the handle brackets attached to the blade substantially in the positions illustrated, that is, at a location substantially rearwardly of the forward flexible ends of the tool.

The use of the tool has effected considerable economy in the construction of so-called dry walls, that is, walls constructed of Wall board, in that the joints or seams of the wall board panels may be expeditiously filled and trimmed, and both inside and outside corner sea-ms can be formed with plaster in a highly expeditious manner inasmuch as very little is left to the dexterity and skill of the mechanic other than to exert a sufficient pressure upon the tool to deflect the operating forward ends thereof in the manner hereinbefore described; The joints thus formed, while being substantially uniform, must follow the converging surfaces of the wall panels which form the corner structures and any film of plaster which overflows from the immediate joint region onto the panel surfaces adjacent the corner seams will be feather edged relative to the panel surfaces, thus eliminating most of the sanding operation hereto-fore found necessary before decorative media could be applied to a seamed dry wall structure.

It is to be understood that While I prefer to provide the tools with a good grade offlexible Steel, other flexible materials, such as plastic blades, may be found satisfactory for the purposes stated.

While I have shown the stop structure 26a on the inside corner forming tool. a similar stop may also be provided and conveniently shaped integral with the handle stamping l to limit the extent of deflection of the blades l0 and Il. By the employment of stops, considerable pressure may be applied to the tools to effect the feather edging should the plaster become less pliable during the completion of a job. The use of stops also serve to center the blade ends when deflection pressure is applied to the tool, thus assisting the user in maintaining a centered or aligned relationship to the corner line to be formed.

I claim:

l. A plaster and cement trimming trowel for forming corner lls or joints comprising two blade portions converging to form a dihedral angle and having a common handle, the blade portions being formed of manually flexible sheet material with the trimming edges thereof converging toward a common point on the dihedral edge of said dihedral angle to provide a corner forming apex, the adjacent edge portions of the blades between said handle and apex being physically separate to allow displacement of the adjacent blade edges relative to each other when the blades are flexed in use.

2. A trimming tool for forming plastered corners of wall board structures comprising two plain surface manually flexible metal troweling blades mounted on a common handle in troughlike relation with the forward plaster trimming edges thereof disposed at an oblique angle relative to each other, and with the inner, adjacent edge portions of the blades between the handle and the trimming edges physically separate to allow relative displacement, whereby the trimming edges may be flexed by manual effort to form substantially a right angle.

3. A plaster and cement trimming tool for forming corner joints comprising two blade portions converging to form a dihedral angle and having a common handle, the blade portions being formed of manually Ilexible sheet material with the trimming edges thereof converging toward a common point on the dihedral edge of said dihedral angle to provide a corner forming apex, the edge portions of the blades adjacent the dihedral edge and inward of said apex being physically separate to allow vdisplacement relative to each other when the blades are flexed in use, and the angle between said trimming edges being less than the plane angle of said dihedral angle.

4. A plaster and cement trimming tool for forming corner joints comprising two planular blade portions formed of manually flexible sheet material and a common handle mounting said blade portions relative to each other to form a dihedral angle, trimming edges being formed on said blade portions convergent toward a common point in the edge of said dihedral angle to provide a corner forming apex, the trimming edges being equally oblique to the said dihedral edge and forming relative to each other an angle less than the plane angle of said dihedral angle, and the blade portions being separate from each other along the adjacent edges inward of said apex whereby separate adjacent edges of the said blade portions are relatively movable when the blade portions are flexed in use.

5. A tool such as that described in claim 4, in which the handle is attached to the blade portions on those sides of the blade portions including a dihedral angle of less than 6. A tool such as that described in claim 4 in which a space is provided between the said blade portions extending inward convergently from the said corner forming apex in the general direction of the dihedral edge.

7. A tool such as that described in claim 6, in which a blade stop member is associated with the handle, said stop member extending from the handle and being provided with a blade abutment portion spaced from the blade portions inwardly from said apex for supporting the flexible trimming edge bearing ends of said blade portions when the tool is flexed in use.

8. A tool such as that described in claim 4, in which the handle attached to the blade portions on those sides of the blade portions including a dihedral angle of more than 180.

SAMUEL T. SHIELDS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 515,890 Walrath Mar. 6, 1894 1,370,060 Smith Mar. l, 1921 1,654,449 Benzing Dec. 27, 1927 1,899,183 Cruz Feb. 28, 1933 2,420,062 Ames May 6, 1947 

